Drainage bag

ABSTRACT

A drainage bag for receiving bodily waste, such as an ostomy bag, comprises an outer bag of material soluble in cold water,e.g. polyvinyl alcohol, and an inner bag of material insoluble in water at ambient temperature and body temperature but soluble in organic solvent,e.g. 2-oxepanone polymer (polycaprolactone). When the bag (and contents) are to be disposed of, appropriate organic solvent (e.g. benzyl alcohol) is applied to the inner bag. The bag can then be placed in a WC bowl and is flushable after about 1-2 minutes.

FIELD OF THE INVENTION

This invention concerns drainage bags for receiving bodily waste,particularly ostomy bags or pouches for receiving waste from colostomy,ileostomy and urostomy patients, urine pouches and the like.

BACKGROUND TO THE INVENTION

Ostomy bags are in widespread use for collecting unabsorbed or excretedbodily waste material from the digestive tracts of colostomy, ileostomyand urostomy patients. Disposal of used ostomy bags and their contentspresents a serious practical problem for users. This has led to variousproposals for ostomy bags that can be disposed of (with contents) bybeing flushed down a conventional domestic water closet (WC). Potentialproblems that arise in this connection include bags floating and failingto flush and bags flushing but causing blockage of drains. Flushableostomy bags should also ideally be biodegradable, for environmentalreasons.

GB 2083762 discloses a C-disposable ostomy pouch made of composite sheetmaterial comprising an inner layer of mechanically weaker,water-impermeable material, e.g. polyvinylidene chloride (PVDC) and anouter layer of mechanically stronger, water-soluble or disintegratablematerial, e.g. appropriate grades of polyvinyl alcohol (PVA).

WO 94/12128 discloses an ostomy bag comprising a water-impermeable outerbag, e.g. of polyvinyl chloride (PVC) and a water impermeable inner bag,e.g. of polyvinyl alcohol (PVA) of a grade that is slowly soluble incold water. The outer and inner bags are detachably secured togethersuch that when the bag has been used and is ready for disposal, theouter bag is detached from the inner bag for separate disposal, e.g. ina domestic household waste bin. The inner bag and contents are removedfrom the body of a user and can be flushed away down a WC.

Another approach is to provide flushable ostomy bags comprisingpH-sensitive material. See, e.g., GB 2195919 and U.S. Pat. No.5,417,677.

WO 96/37171 discloses other approaches including flushable ostomypouches comprising water-insoluble but organic solvent-solublematerials.

SUMMARY OF THE INVENTION

The present invention provides a drainage bag for receiving bodilywaste, comprising an outer bag of material soluble in cold water (at atemperature in the range 5 to 25° C.) and an inner bag of materialinsoluble in water at ambient temperature (up to about 40° C.) and bodytemperature (about 38° C.) but soluble in organic solvent.

In use, the drainage bag is attached to or associated with the body of auser in appropriate manner to receive bodily waste. The inner bag, beingof material insoluble in water at ambient temperature (up to about 40°C. depending on climate and other circumstances, typically about 20° C.in a temperate climate) and body temperature (about 38° C.), retainswaste received therein. The outer bag provides additional strength andcan also provide good odour barrier properties to the drainage bag as awhole. When the drainage bag (and contents) are to be disposed of, thebag is removed from the body of the user. Appropriate organic solvent isapplied to the inner bag in a number of possible ways to be discussedbelow. The bag is placed in a WC bowl and the WC flushed. The inner bagdissolves in the solvent, at least to a sufficient extent to beflushable, and the outer bag dissolves in the water in the WC bowl, atleast to a sufficient extent to be flushable, typically within about 1to 2 minutes, enabling the bag and contents to be flushed away withoutcausing blockage of drains. Any undissolved outer bag material willdissolve completely over time, e.g. over the course of a few days. Anyundissolved inner bag material is preferably biodegradable and subjectto attack by microbes in sewage treatment works.

The inner bag conveniently comprises 2-oxepanone polymer (also known aspolycaprolactone), polyester amide or copolyester having suitablesolubility properties. Suitable materials are commercially available,with suitable 2-oxepanone homopolymers including CAPA FB 100polycaprolactone (CAPA FB 100 is a Trade Mark) from SolvayCaprolactones, Solvay Interox Ltd. Suitable polyester amides includematerials known by the Trade Marks BAK 1095 and LP BAK 404-004 fromBayer. The copolyester is convenientlypoly(tetramethyleneadipate-co-terephthalate) e.g. in the form of EastarBio GP copolyester (Eastar Bio GP is a Trade Mark) from Eastman ChemicalCompany. The polycaprolactone may be plasticised, e.g. using a citrateester, to enhance softness. All of these materials also have theadvantage of being biodegradable. All of the above materials areinsoluble in water at temperatures of up to at least 40° C. but arerapidly soluble at. ambient temperature in the organic solvent benzylalcohol, dissolving substantially completely within 1 to 2 minutes.Benzyl alcohol is a convenient solvent to use, being non-flammable,non-toxic, cheap and readily available. Other possible solvents includetoluene, glacial acetic acid and N-methyl pyrrolidone, but these havethe respective disadvantages of being highly flammable, corrosive andless effective under water.

The outer bag may be made from a wide range of materials soluble in coldwater (i.e. at a temperature of WC flush water (which may vary betweenabout say 5° C. and 25° C. depending on factors including climate,typically being about 15° C. in a temperate climate)), includingpolyvinyl alcohol (PVA), hydroxypropyl methyl cellulose (HPMC),polyethylene oxide etc. Suitable materials are commercially available.The outer bag is preferably made of biodegradable material; all of thematerials listed above are biodegradable. The currently preferred outerbag material is PVA, which is available in a wide range of grades havingsuitable solubility properties, such as partially hydrolysed grades ofPVA with a temperature of dissolution in the range of 5° C. to 30° C. Anexample of a suitable commercially available PVA is Mono-sol M-7030(Mono-sol M-7030 is a Trade Mark) from Chris Craft Industrial ProductsInc., which has a temperature of dissolution of about 10° C. PVA alsohas the advantage of having good odour barrier properties. It is furtherpreferred to use a film of PVA coated with or incorporating alginate orgelatin, to improve odour barrier properties. Such a coating is providedon one face only of the film material, forming the outwardly facing faceof the bag. The coating conveniently comprises two layers, a tie coatand a top coat.

The odour barrier properties of the outer bag material may be furtherenhanced by including in or on the material odour-absorbing material,e.g. in the form of clay particles such as nanoclay materials availablefrom Nanocor Inc.

The organic solvent may be applied to the inner bag in a number of ways,including those disclosed in WO 96/37171. These include providing acontainer, e.g. sachet, containing a suitable dose of solvent (e.g.about 0.5 ml) within the inner bag or between the inner and outer bags,the container being rupturable, e.g. by application of external force,to release the solvent contents and thus result in the solventcontacting the inner bag. As a further possibility, the drainage bag maybe provided with a valved inlet leading from the exterior to either theinterior of the inner bag or the space between the inner and outer bags,enabling solvent to be introduced and so brought into contact with theinner bag. To this end, the user may be provided with a container ofsolvent, e.g., a pressurised spray or pump action device, possiblydesigned to delivery a metered dose of suitable size of the solvent,e.g. 3 or 4 sprays of solvent, amounting to a total of about 0.5 ml.Another possibility is for the outer bag to include a removable portion,e.g. a tear-off panel, for removal by a user, to expose the inner bag.Alternatively, a portion of the outer bag may be penetrated, e.g. by useof a pierce point provided to the user. The user then applies solvent tothe inner bag, e.g. from a container as discussed immediately above.

The bag may thus be sold together with a supply of appropriate solvent,with the solvent preferably dispensable in metered doses of appropriatesize.

The drainage bag is typically embodied as an ostomy bag. In this case,the bag includes suitable means for attaching the bag to the body of auser. Such means typically comprise an annular flange or wafer on theexterior of the bag, surrounding respective inlet apertures in the outerand inner bags through which bodily waste can pass to be collected inthe inner bag. The inlet aperture in the outer bag is preferably largerthan the inlet aperture in the inner bag, with the flange attached toannular portions of both the inner and outer bag walls. In this way theflange acts to protect the outer bag (which is made of coldwater-soluble material) from contact with the bag contents in normaluse. The flange conveniently functions to secure the inner and outerbags together. The flange is suitably made of hydrocolloid material,e.g. carboxymethylcellulose or polyisobutylene or mixtures of thesematerials. The hydrocolloid flange material functions as an adhesive,enabling adhesion to the skin of a user. The inner surface of the flange(for attachment to the baa wall) may be laminated to a film of materialsoluble under the same conditions as either the outer bag material (iesoluble in cold water) or the inner bag material (ie insoluble in waterat ambient temperature and body temperature but soluble in organicsolvent). The laminate film material is preferably biodegradable, and ispreferably polycaprolactone, polyvinyl alcohol or polyurethane. Thelaminate film material is preferably also attached directly to the bagwall material, eg using a suitable adhesive or by heat sealing. Forexample, where the flange is laminated to a film of polycaprolactone, aheat seal can be used to attach the polycaprolactone to the inner bagmaterial and adhesive can be used to attach the polycaprolactone to theouter bag material. Where the flange is laminated to a film of polyvinylalcohol, adhesive can be used to attach the polyvinyl alcohol to theinner bag material and heat sealing can be used to attach the polyvinylalcohol to the outer bar material.

The means for attaching the bag to the body of a user may alternativelycomprise a two-part body attachment, including a base portionsemi-permanently mounted around the abdominal opening of a user, withthe flange or wafer of the bag sealingly engaging in known manner withthe base portion.

The drainage bag conveniently includes a gas valve to permit escape offlatus gases from the bag. The valve may have an associated odourfilter, in known manner.

The drainage bag desirably has on at least the surface thereof adjacentthe body of a user, in use, a layer of soft material (known as a comfortpanel) e.g. of woven viscose or cotton bonded by water dispersible PVA.

The invention will be further described, by way of illustration, withreference to the accompanying drawings, in which:

FIG. 1 is a schematic sectional view of one embodiment of an ostomy bagin accordance with the invention; and

FIG. 2 is a front view of the bag of FIG. 1 on a larger scale.

Referring to the drawings, the illustrated ostomy bag 10 comprises anouter bag 12 having a front panel 14 and a rear panel 16. Panels 14 and16 each comprise a film of Mono-sol M-7030 cold water-soluble PVA 75 μmthick, coated with alginate on one face thereof (which forms the outerface of the bag). The coating comprises two layers, as follows:

-   -   1) A tie coat applied at 10 gsm.

The dried tie coat consists of the following percentage by weight solids49.7% Polyvinyl alcohol 29.0% Sodium alginate 20.5% Glycerin  0.8%Preservative, i.e. 2-bromo-2-nitropropane-1,3-diol

-   -   2) A top coat applied at 50 gsm

The dried top coat consists of the following percentage by weightsolids: 66.0% Sodium alginate 33.0% Glycerin  1.0% Preservative, i.e.2-bromo-2-nitropropane-1,3-diol

The two panels 14 and 16 are secured together by heat sealing aroundtheir periphery, as shown at 18, to form a bag. The front panel 14includes a circular opening 20, constituting an inlet to the bag.

The bag 10 further comprises an inner bag 22 having a front panel 24 anda rear panel 26. Panels 24 and 26 each comprise a film of CAPA FB 100polycaprolactone 25 μm thick secured together by heat sealing aroundtheir periphery, as shown at 28, to form a bag. The front panel 24includes a circular opening 30, constituting an inlet to the bag.

The circular opening 20 of the outer bag has a larger diameter than thecircular opening 30 of the inner bag. This is to protect thewater-soluble film of the outer bag from excreted bodily waste. Theinner and outer bags are not physically attached directly to each other.A flange or wafer 34 of hydrocolloid material (a mixture ofcarboxymethylcellulose and polyisobutylene) with a polycaprolactonebacking layer (not shown) laminated thereto is secured to the outer faceof panel 14 and panel 24 in the areas labelled a and b, respectively,thus functioning sealingly to secure the inner and outer bags together.The wafer backing layer of polycaprolactone is attached to panel 14 byuse of a suitable adhesive and is attached to panel 24 by use of heatsealing.

A layer of woven viscose material (not shown), constituting a comfortpanel, is provided on the outer surface of front panel 14, surroundingflange 34, and on the outer surface of rear panel 16.

The rear panel 16 of the outer bag includes a removable portion,represented at 38.

The bag has an overall length of about 205 mm and an overall with ofabout 145 mm, with a maximum capacity of 250 ml to 300 ml.

In use, the bag 10 is fitted to the body of a user by adhering flange 34to the abdomen of a user, surrounding the abdominal opening. Unabsorbedor excreted bodily waste passes into the bag 10 through openings 20 and30 and collects in the inner bag 22.

When the bag 10 is to be disposed of, the bag is removed from the bodyof the user. The comfort panel is removed either with a pull strip or bymeans of a large overlapped split in the comfort panel on the rear panel16 that allows access to the rear face of the bag (remote from the bodyin use). Portion 38 of rear panel 16 is removed, e.g. by tearing withthe assistance of a peel back tab (not shown), and an appropriate dose(about 0.5 ml) of benzyl alcohol applied to the surface of the inner bag22, by spraying from a container (not shown). The bag is placed in a WCbowl, where the comfort panel disperses and the outer bag starts todissolve in the water in the WC bowl and the inner bag dissolves in theapplied benzyl alcohol, allowing the bag contents to escape into the WCbowl. After a minute or so, the bag is sufficiently dissolved to be influshable condition, along with the bag contents, and can be disposed ofby flushing the WC.

1. A drainage bag for receiving bodily waste, comprising an outer bag ofmaterial soluble in cold water and an inner bag of material insoluble inwater at ambient temperature and body temperature but soluble in organicsolvent.
 2. A drainage bag according to claim 1, wherein the inner bagcomprises 2-oxepanone polymer (polycaprolactone), polyester amide orcopolyester.
 3. A drainage bag according to claim 1 or 2, wherein theouter bag comprises polyvinyl alcohol, hydroxypropyl methyl cellulose orpolyethylene oxide.
 4. A drainage bag according to claim 3, wherein theouter bag comprises polyvinyl alcohol coated with or incorporatingalginate or gelatin.
 5. A drainage bag according to any one of thepreceding claims, wherein the inner bag comprises 2-oxepanone polymer(polycaprolactone) and the outer bag comprises polyvinyl alcohol.
 6. Adrainage bag according to any one of the preceding claims, including aflange for attachment to the body of a user and secured with respect tothe inner and outer bags, surrounding respective inlet aperturestherein.
 7. A drainage bag according to claim 6, wherein a layer of filmmaterial soluble under the same conditions as either the outer bagmaterial or the inner bag material is laminated to the surface of theflange remote from the body of a user, in use.
 8. A drainage bagaccording to claim 7, wherein the laminated film material is selectedfrom 2-oxepanone polymer (polycaprolactone), polyvinyl alcohol andpolyurethane.
 9. A drainage bag according to claim 7 or 8, wherein thelaminated film material is attached directly to the bag wall material.10. A drainage bag accordingly to any one of claims 6 to 9, wherein theinlet aperture in the outer bag is larger than the inlet aperture in theinner bag.
 11. A drainage bag accordingly to any one of the precedingclaims, in combination with a supply of organic solvent for the innerbag material.
 12. A drainage bag according to any one of the precedingclaims, comprising an ostomy bag.